Why do I have a persistent code 501 in 94 santa fe?

Question

I replaced the speed sensor (with gear) at the differential then cleaned and restabed the connections of all transmission sensors and ECU. The code was gone for about 50 miles and then it comes back. Otherwise the car works as it should.

Answer 1

At the differential  ? That the speedometer drive gear. The Wheel speed sensor is at the right front wheel.

Read more :https://www.autocodes.com/p0501.html